POS0977 ASSOCIATION OF DEMOGRAPHIC AND CLINICAL CHARACTERISTICS OF PATIENTS WITH FAMILIAL MEDITERRANEAN FEVER AND AXIAL SPONDYLOARTHRITIS WITH THE M694V MUTATION
Authors: M. Kiraci, E. Bilgin, E. Duran, B. Farisogullari, E. C. Bolek, G. K. Yardimci, Z. Özsoy, G. Ayan, G. Sandal Uzun, T. H. Akbaba, B. B. Peynircioglu, O. Karadag, A. Akdoğan, Ş. A. Bilgen, S. Kiraz, A. İ. Ertenli, U. Kalyoncu, L. Kiliç
Journal: Annals of the Rheumatic Diseases (2022)

Background The incidence of co-occurrence of FMF and axial spondyloarthritis (axSpA) in adults is reported to be 0.5-7.5%. M694V mutation is the most frequent variant in patients with FMF+AxSpA (1). Objectives To evaluate the association of demographic and clinical characteristics of patients with FMF+axSpA with the M694V mutation. Methods A total of 9630 FMF patients were identified according to the ICD-10 code (E85.0) in the electronic database of Hacettepe University Hospital. 7525 patients aged &lt;18 years old and no hospital admissions after 2014 were excluded. 2105 adult FMF patients screened for accompanying axSpA according to ICD-10 code (M45) and 241 patients detected as FMF+axSpA. FMF diagnosis was confirmed with Tel-Hashomer criteria. The diagnosis of axSpA was confirmed by the presence of sacroiliitis on sacroiliac radiography according to the Modified New York (mNY) criteria or the presence of active sacroiliitis on sacroiliac magnetic resonance imaging according to the ASAS criteria. According to these criterias, the diagnosis of FMF+AxSpA association was confirmed in 136 patients. MEFV gene result was present in 113 (83%) of 136 patients and were included in the study. Patients were divided into two groups as M694V (+) and M694V (-) according to the M694V mutation, and the demographic and clinical characteristics of the patients were compared. p&lt;0.05 was considered statistically significant. Results Of 113 patients with known MEFV gene result, 91 (80.5%) were M694V (+), 22 (19.5%) were M694V (-), 45 (39.8%) were homozygous for M694V. In the M694V (+) group, symptom onset and diagnosis of both FMF and axSpA were at an earlier age compared to M694V (-) patients (p&lt;0.05). The frequency of radiographically proven moderate to severe hip involvement (24.2% vs. 9.1%) and total hip replacement (11% vs. 4.5%) was higher in M694V (+) patients. However, these differences were not statistically significant (p=0.12; p=0.36). In the homozygous M694V (+) group, symptom onset and diagnosis of both FMF and axSpA were significiantly at an earlier age than in the group homozygous M694V (-) (p&lt;0.001). Although erysipelas-like skin rash was more common in homozygous M694V (+) group (28.9% vs. 11.8% p=0.02), other symptoms and findings were similar in both groups (Table 1). Table 1. Features M694V (+) (n=91 ) M694V (-) (n=22 ) P1 M694V Homozygous (n=45 ) M694V Nonhomozygous (n=68 ) P2 Age at FMF symptom onset [years, med (25-75)] 11 (5-18) 21 (8-30) 0,005 7 (1-42) 18 (3-53) &lt;0,001 Age at FMF diagnosis [years, med (25-75)] 18 (10-27) 33 (27-38) &lt;0,001 12 (1-42) 28 (3-59) &lt;0,001 Age at AxSpA symptom onset [years, med (25-75)] 20 (15-25) 29 (24-38) &lt;0,001 20 (5-50) 22 (5-58) 0,43 Age at AxSpA diagnosis [years, med (25-75)] 24 (19-33) 37 (28-44) &lt;0,001 23 (11-51) 29 (7-59) 0,039 Fever n (% ) 84 (92,3) 21 (95,5) 0,60 44 (97,8) 61 (89,7) 0,10 Abdominal pain n (% ) 80 (87,9) 20 (90,9) 0,70 43 (95,6) 57 (83,8) 0,056 Peripheral arthritis n (% ) 45 (49,5) 7 (31,8) 0,13 24 (53,3) 28 (41,2) 0,20 Erysipelas n (% ) 19 (20,9) 2 (9,1) 20,2 13 (28.9) 8 (11,8) 0,02 Enthesitis n (% ) 21 (23,1) 4 (18,2) 0,62 11 (24,4) 14 (20,6) 0,63 Uveitis n (% ) 11 (12,1) 4 (18,2) 0,45 4 (8,9) 11 (16,2) 0,26 Psoriasis n (% ) 6 (6,6) 1 (4,5) 0,72 2 (4,4) 5 (7,4) 0,82 HLA-B27 (+) n (% ) 25 (27,3) 4 (18,2) 0,54 2/15 (13,3) 12/40 (30) 0,30 Syndesmophyte n (% ) 20/82 (24,4) 6/19 (31,6) 0,52 7/43 (16,3) 19/59 (32,2) 0,07 Total ankylosis n (% ) 4/83 (4,8) 1/19 (5,3) 0,94 1/43 (2,3) 4/59 (6,8) 0,39 Moderate to severe hip disease * n (% ) 22 (24,2) 2 (9,1) 0,12 12/45 (26,7) 12 (17,6) 0,25 Total hip replacement n (% ) 10 (11,0) 1 (4,5) 0,36 4 (8,9) 7 (10,3) 0,80 * BASRI-hip score ≥3 on any side Conclusion FMF and SpA symptoms appear at an earlier age in M694V positive patients. The M694V mutation is associated with severe disease and early disease onset. References [1]Kaşifoğlu T, Calişir C, Cansu DU, Korkmaz C. The frequency of sacroiliitis in familial Mediterranean fever and the role of HLA-B27 and MEFV mutations in the development of sacroiliitis. Clin Rheumatol. 2009;28(1):41-6. Disclosure of Interests None declared